Megger INGVAR, User Manual

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30 ZP-BH05E BH0654BE
6 HOW TO INSTALL INGVAR
6.9 How to arrange the
cable sets
Minimising impedance in cables
Just increasing cross-section area helps only to a cer-
tain extent. When resistance is low, the major part of
the impedance is caused by the reactance. Minimising
the magnetic flux will reduce the reactance:
A]
If cables not can be twisted, keep cables with
same current direction away from each other
as much as possible
B]
Avoid loops or “windows”.
It is sometimes not possible or practical to twist the
cables. However any action to keep cables with op-
posite current direction close together and to mini-
mise loops helps. If the distances to the test object
terminals are different it is better to use cables with
different lengths in order to avoid loops.
Current Unit with twisted 2 pairs Multi-cable Set
Cables pair-twisted over their entire length.
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